Have nearly finished restoring my C5 and now need to buy a battery - the original Sinclair battery that came with it is unsurprisingly dead!

Which is the best battery to use?

What happens with the battery cover connections as any replacement battery will have different terminals to the Sinclair originals?

Thank you.

There are loads of posts on this subject if you search. LIPO batteries are very expensive, car batteries cheap but not as good as a leisure battery for this use. From memory a 80/85 Amp leisure battery fits the space but not a 100/110 Amp one. I purchased mine from a local caravan accessory shop, or try eBay. A 3rd choice, you may adapt the original Sinclair battery top to fit your new battery. That has either helped or completely confused you!!!

I agree with Ray1, the car battery or 80 - 85 Ah leisure battery work fine( The leisure battery weighs about 19 kg, which is a lot of weight to lug around), but go for the C5 Alive safety kit, otherwise you'll be needing to repair the Pod, and the control box if you get the polarity wrong, and your C5 Motor won't run! (Chas sometimes makes them too - PM him)

http://www.ebay.co.uk/itm/SINCLAIR-C5-SAFETY-POWER-WIRING-SET-UP-C-5-/221659635076?pt=UK_SportsLeisure_Cycling_Bike_Lights&hash=item339bf19d84

There are a few brave souls out there who have fitted Lithium bateries in the original battery case, then you can keep the original look. Me I went for Lithium batteries, very expensive, but a 40 Ah lithium set up weighs less than 6kg, and has the same range capabilities as the 80 Ah leisure battery, and in theory should last longer. The lithium batteries don't fade the way lead acids ones do when running, so I've found performance is more consistant. A 10 mile run recently was showning no sign of slowing down, where my speed would have been dropping off on the Lead Acid one.

I use two of these connected in Parallel, came with a charger.

http://www.ebay.co.uk/itm/Ultra-Max-12v-20Ah-LiFePO4-18-Hole-Lithium-Golf-Trolley-Battery-/120901844487?pt=UK_Golf_Trolleys&hash=item1c264fbe07

If cost is an issue get a used 063 battery from a Scrap yard and have some fun it'll fit fine and give you 8 - 10 miles of C5 grin.

For wiring kits don't forget Chas sells these on ebay cheaper than other wiring kits As for lithium batteries, if you have the money they are very much recommended if you use the C5 a lot.

Don't forget you can always double up with 2
Battery's in parallel

Just to confuse you even more.

If you wish to retain the original cover and don't mind using a starter battery, go for a type 038 battery, but you will also need pole adapters.

http://www.ebay.co.uk/itm/Pair-of-Post-Battery-Terminalsttery-Terminals-Car-Boat-Caravan-Motorhome-/351197298784?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item51c4fd8060

LIPO is the way to go, assuming you have the cash, but you will also need a special charger as well. The C5 was designed for leisure type batteries, but I don't think you'll find a suitable battery (size, pole type, plus pole to the left) to match the cover.

Hope this is of some help.

Thank you for help so far. Have fitted a power cable kit and connected to a spare car battery - everything worked!

Now looking for a 80Ah leisure battery to fit permanently but struggling to find one on Ebay and other sites that fits. Any recommendations / info'/ suggestions gratefully received.

Thank you

Hi there you find that it is easer to find a 75amp / 85amp either will fit
Bye Chas

Hi,

this is a recommendation from C5Mick.

http://www.ebay.co.uk/itm/251360016424?ru=http%3A%2F%2Fwww.ebay.co.uk%2Fsch%2Fi.html%3F_from%3DR40%26_sacat%3D0%26_nkw%3D251360016424%26_rdc%3D1

I don't think you'll be able to beat this.

what sort of range do these ones give?

Hi,

what sort of range do these ones give?

That's almost the same as asking how long is a piece of string.

All the necessary info is missing. How much you weigh, temperature, pedal assistance or no pedal assistance, what the local terrain is like.

But one thing is certain. it'll be a lot further than the original battery would take you. But take into consideration if a 50aH battery achieves 25 miles, a 100aH battery will not give you double the distance due to the extra weight.

point taken! I've seen people talk about lithium polymer ones, and ping batteries is a name that keeps cropping up - although I notice that they only seem to advertise 24 V minimum at the moment. Is a 12V lithium from them a custom product you order then, or is there a particular model number I can't spot on there that is popular for C5 use?

how about something like this (deep pockets only) - http://www.ebay.co.uk/itm/100Ah-12V-LITHIUM-LiFePO4-Battery-for-Leisure-Solar-Wind-and-Off-grid-12-volt/131402654613?rt=nc

Again for deep pockets.

http://www.ebay.de/itm/120901844487?_trksid=p2060778.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

[quote=offyoutoddle;4904]Ive seen people talk about lithium polymer ones, and ping batteries is a name that keeps cropping up - although I notice that they only seem to advertise 24 V minimum at the moment. [/quote] Ping batteries will make you 12V lifepo batteries to any capacity, just drop them an email. I'm running one of their 60ah 12v batteries and its good for 40-45 mile easily for me. Very expensive though, but they work out cheaper in the long run if you use the C5 a lot, and because of their light weight, they make pedaling a C5 a breeze One important note when ordering any lithium battery from ping (and other places I assume) is to make sure they do not include a high current cutout circuit. Ping will do this if asked.

[quote=offyoutoddle;4904]how about something like this (deep pockets only) - http://www.ebay.co.uk/itm/100Ah-12V-LITHIUM-LiFePO4-Battery-for-Leisure-Solar-Wind-and-Off-grid-12-volt/131402654613?rt=nc [/quote] Looks great if you can afford it. That would do a good 60 miles I think

how about something like this (deep pockets only) - http://www.ebay.co.uk/itm/100Ah-12V-LITHIUM-LiFePO4-Battery-for-Leisure-Solar-Wind-and-Off-grid-12-volt/131402654613?rt=nc

Why not take up their 10% offer?

EXTRA 10% OFF WHEN YOU BUY 10 OR MORE

[quote=Dan;4907][quote=offyoutoddle;4904]Ive seen people
talk about lithium polymer ones, and ping batteries is a name that keeps
cropping up - although I notice that they only seem to advertise 24 V
minimum at the moment.
[/quote]
Ping batteries will make you 12V lifepo batteries to any capacity, just drop them an email. I'm running one of their 60ah 12v batteries and its good for 40-45 mile easily for me. Very expensive though, but they work out cheaper in the long run if you use the C5 a lot, and because of their light weight, they make pedaling a C5 a breeze

One
important note when ordering any lithium battery from ping (and other
places I assume) is to make sure they do not include a high current cutout circuit. Ping will do this if asked.[/quote] So with the lipo battery, how do you find hill climbing? Do you still need to peddle as much? If so is it noticeably easier without the weight of a lead acid battery? if you picked up one of those golf cart batteries, would that have a high voltage cutout do you think? i'm wondering if that's a cheaper option than going to Ping

If i was going to go for a Lithium battery, is a 20Ah one worth it, or is it better to go for a 40Ah one? To qualify what I mean, i think a 40Ah is half as much again as the 20Ah in terms of price. The question is, what sort of range increases would a 40Ah give over a 20Ah? The reduction in weight would be a factor here too I guess, as the 20Ah is much lighter. I'm just wondering if it is worth it - I'm assuming a 20Ah could give as much as 10-15 miles though is that fair?

Me thinks your estimation is a little more than being optimistic. If weight was such a critical factor I would suggest a pack of 8 AAA (Micron) batteries, this should give you a range of 50 miles, or 10 rechargeables would work out cheaper in the long run.

Hahah don't be daft ;)

Seriously though - How so? I'm going by what I've seen quoted elsewhere that a small 20Ah pack can give the 10-15 mile figure. I'm not suggesting the 40 will give double because it's bigger. I'm also not suggesting that a pack half the weight does twice the range, merely recognising contributing factors.

I'm just trying to get an idea of

1) if a 20Ah pack is good for the 15-20 miles I saw claimed once
2)is the increase in cost to go to a 40ah pack accompanied by a similar increase in magnitude in range. You know, twice the price for half as much extra range, that sort of finger in the air stuff

I once bought an electric bike, the vendor claimed up to 50km range. I found that even with pedal assistance 15km was the limit. The vendor didn't lie, after all 15km is up to 50km, his claim was just exaggerated.

The original C5 gave a range of 15 to 20 miles (38ah IIRC), so I find the same figure for a 20ah battery, even though lighter, to be suspect. But, there again I'm not an expert on new battery technology.

If your pockets are not deep, and you don't have short arms, then I would recommend the larger battery. A battery life is often measured by the number of times it can be recharged. Now for an extreme example, to cover a total distance of 1000 miles a small battery will need to be recharged more often than a large battery, thereby having to be replaced more often.

On the other hand, if a 20ah battery is exactly half the price of a 40ah, then I'd go for two batteries. I bought two identical batteries at the same time, one gave up the ghost after a short time, the other is still going strong.

And with sod's law, the battery always gives out just at the point it shouldn't.

If you are not in a hurry wait for the Graphene supercapacitors, they can be charged in seconds, weigh next to nothing, and are super light. Capacity can be brought up to that of a battery. They are in use at the present time, but price is not known to me at the moment. It's claimed they will be a lot cheaper than batteries, and may well be the end of conventional batteries.

Cheers for the advice Karl much appreciated. I think a leisure battery is the cheap answer but the weight with all the hills round here and the slow recharge time is what bothers me. Food for thought!

Lithium batteries are the lightest, and thanks to pukert's law, (see link), they give a better range for a smaller Ah ratings.

http://batteryuniversity.com/learn/article/calculating_the_battery_runtime

http://www-scf.usc.edu/~rzhao/LFP_study.pdf

But hey this is for fun - go enjoy the 80Ah Leisure Battery :-)

the only thing that worried me about the leisure batteries was the weight - specifically going up hills. Bang for buck, it gives a range you won't complain about I'm sure. Its specifically the weight causing hill climbing issues. Maybe I'm just overly worried, as I have no idea how bad it would be to pedal a c5 up the long hill local to me here with a over 13kb of lead in the back ;)

Oh and recharge time. Lead acid batteries one drained mean your fun is over for the day for sure.

I've got 40ah lithium fitted, and have yet to travel much further than 12 miles, but that's because I've not tried to. I need to find a decent test track and run the battery down to 10.5 v. After 12 miles my voltage had dropped from 13.6 to 12.9 v so I have a fair distance left to go. Lower estimate for 60 ah is about 45 miles in the thread above, so I'm guessing mine would be good for about 30 miles.

I have however seen these batteries being spoken about on EV forums, http://www.ev-power.eu/Sinopoly-40Ah-300Ah/?cur=1 and 4 40 ah in series would give 13.6 volts, and probably in excess of 100miles range on a C5. Costs way less than anything else I've found. Looks to be about the 160 quid mark for the batteries and connectors! Built for traction application so no problem on the C5

Anyone else tried these?

Oh and they would only weigh about 6kg!

Hi jocky,

you've got me lost with your figures.

4 x 3.6v @ 40Ah in series gives you 14.6v @ 40Ah.
4 x 3.6v @ 40Ah in parallel gives you 3.6v @ 160Ah.

So 4 in series ain't gonna give you 100 miles. If you put 8 in series/parallel then you double the capacity.

But I must admit the price looks great.

Bye the way, my middle name is Killjoy.

I think jockywilson11 is talking about 30 miles on 40Ah with 4 LiFe cells in series. I think it might give you something about 35 miles even. Anyway the calculation depends on what is the maximum voltage you are going to charge the cells. I reckon you've taken 3.4 as a figure for LiFe, seems OK although those could go up to 3.5 or 3.6 like Karl has suggested.

Either way it's better to take Wh instead of Ah so voltage is less important As long as you're not really considering motor efficiency curve and vehicle speed ;-) With nominal voltage (let's take it as average) 4 40Ah LiFe will give something around 512Wh. My 2 chinese e-bikes have 216Wh LiPO batteries and they can go up to 18 miles on that with just a small help of pedals.

Hi rusala,

your quote:

I think jockywilson11 is talking about 30 miles on 40Ah with 4 LiFe cells in series.

jockywilson11's quote

and 4 40 ah in series would give 13.6 volts, and probably in excess of 100miles range on a C5.

It's easy to be mislead by facts if you haven't studied in the subject concerned.

But as jockywilson11 pointed out, the great advantage in weight reduction. This alone will increase the range.

Taking your figure of 18 miles into consideration, with the increased weight and additional rolling resistance of the C5 you will be very lucky to achieve 30 miles.

Independent tests with the original battery gave 12 to 15 miles depending on the road and weather conditions.

As my Avatar says - doh!

Well it would still be a cheaper option than buying the golf trolley batteries I have now:-) about half the price. At least I got that right!
These cells are from the Czech Republic, so getting them anywhere in Europe wouldn't be a problem, and there would be no import or VAT taxes on them, the price on the site would be the price you pay.

Anyway I'm off to fit a 100w solar cell to the C5 then I can charge up when I'm stopped. Maybe use it for some commuting :-)

Hi jocky,

are you going to use flexible or rigid cells, and how are you proposing to mount them?

I had the idea of mounting a generator in a trailer to charge the batteries underway, but I read somewhere that this is not allowed as an unregistered vehicle.

As I mentioned, the batteries you recommended look to be very good. So I'll be buying some within the next two weeks. Just hope they are as good as they appear to be, or is there a catch somewhere.

[color=red]Yes there's a catch. their prices do not include 21% VAT, plus there is a higher charge for transport as they are classed as hazardous goods. Additional charges are incurred if you pay by card or PayPal.

Just checked the price for 4 x 40Ah units for delivery to Germany (UK transport costs are higher), it comes out to £177. Funny on their web page they indicate that their quoted price is for more than 5 units, but in their pricing list it's the same amount regardless of the quantity.

Edit in red.[/color]

You have to remember I'm talking about CHINESE "supposedly" 6Ah battery ;-) Also LiFE has better discharge characteristic, plus C5 has much better aerodynamics although with low speed it does not matter. Let's say 30 miles should be realistic.

Anyway, have any of considered batteries from Prius? My friends are using those in other EVs and I'm considering using those as well but also because it's easy to get high voltage out of them which is needed for my current upgrade plan.

Hi rusala.

you quoted.

Anyway, have any of considered batteries from Prius?

Do you mean the Toyota Prius, if yes what's so special about their batteries?

If you read post #22 you will see my comment about only getting 15km with pedaling, this was with new 7Ah batteries. Could be a rotten setup, but others only get about 10km with electric scooters using the same batteries, that is with three batteries instead of my two. OK fatter tyres and more weight.

One other point that should be taken into consideration, the Sinopoly cells that jocky was referring to are lithium iron and not LiPos. This means the cell voltage when fully charged is 4.2 volts and not 3.6 volts. Now comes the question, will the C5 circuitry handle 16.8 volts? With 3 cells there is only 12.6 volts which is a little on the low side.

Personally I'm not prepared the risk the higher voltage, so pity but it's no go with these cells.

After my experience with LiPos in my RC models, I don't think I'll be going in that direction, plus of course the high price involved.

Those batteries are very rugged when it comes both to mechanical and electrical characteristics. Toyota has done a very good job with balancing and keeping a proper charge/discharge values so even few years old Prius batteries are almost like new. Also there is next to nothing self discharge and minimum voltage drop with high current discharge (very low impedance). And if you find a good auction the price per Wh may be similar to the above one.


Estimation of the distance is always a tricky topic when you are talking about different vehicles plus different drivers so let's leave it for tests to determine.

Hi rusala,



in the time I was editing my post you posted, the edit may be of interest.

[color=red]@ jocky[/color]. If you are reading this post, then read the edit to my previous post.

Hi Karl,

http://www.ultramaxbatteries.com/ProductDocs/SLAUMXLI20-12-TECH.pdf

I'm using 2 of these and they cost £189 each! So despite the VAT and delivery the other ones are still a good deal. The high 14.7V they see are really only what you get charging. When it's fully charged and ready to actually run I see 13.6V.

I don't use the C5 control box because I found it to be too unreliable when I was still using a lead acid leisure battery, so I just use it for the lights, horn and indicator. I just run the motor directly with a relay ( and kept the Thermal switch inline with the switch), and run a 12v Fan continuously to keep it cool. So I'm not worried about the delicate electronics blowing because of the slightly higher voltages. I have replaced the pod electronics with a simple combined volt/ammeter to keep an eye on things.

I use a Ctek Lithium battery charger which charges the battery up to 14.4 V then keeps it float charged at about the 13.6 V ( Hence my earlier comments).

On the 100W solar cell I have gone for a flexible unit and have built a lightweight aluminium frame to support it. All to keep the weight down. Also using fibreglass rods to hold it all up. Solid rods at the front and the rear ones are hollow rods to get the wires down through:-) I'll put some pics on the page when I've finished and road tested it. I got the frame built today and hope to get it all fixed and wired up tomorrow.

Cheers Jocky

Hi Jocky,

your batteries are LiPo and those that you intend to buy are lithium iron (LiFi), the LiFi are cheaper than the LiPos. EV-Power offer a LiPo 40Ah battery for about £200 which all said and done is a good price.

By the way the cells you intend to buy have a higher voltage (16.8v as a 4er block.) than your LiPos, so you'll need a new charger.

I must look into the subject that Rusala brought up, this might be a good alternative.

When you've got your panel mounted attach a surround of tassels so it looks like 'the surrey with a fringe on top'.
https://www.youtube.com/watch?v=vH2X8Q15hZY

Hi Karl,
I would like to clear up the voltage of different cell type as I think there is some confusion here. So LiFe (or LiFePO4 to be exact) are the "Lithium iron" batteries and their nominal voltage is LOWER than in regular LiPO and from what I know they are usually more expensive then LiPO but also much more durable.

LiFe:
nominal - 3.2V
max - 3.6V

LiPO:
nominal - 3.6V or 3.7V (type dependant)
max - 4.1V or 4.2V

So you can build a pack with 4 LiFe and get 12.8V of nominal and 14.4V maximum voltage.

Or using regular LiPO 3 cells will give you nominal 11.1V and maximum 12.6. That is a bit low in my opinion and using 4 cells might be better idea. You do not actually have to charge them up to 4.2V because it only gives you maybe 10% of additional energy, you can go with for example 3.9V and this way get 15.6V maximum. This may also make the cells more durable.

My idea is to use different motor anyway so I don't have this problem. Regardless of the needed voltage those LiPOs from Prius are really good batteries even though it is LiPo not LiFe.

Hi Rusla,

you've thrown me a wobbler, the information I quoted is from the IN, so who am I supposed to believe. As I mentioned earlier I'm not clued up on modern batteries, this is why I'm wasting too much time in the IN.

I tried to find my source of info but couldn't remember from which of the multiple sites I'd visited in the last month or so it came. So I call up my surfing history, and almost fell of the chair, over 3200 entries. Anyway to cut a long story short,in the end I found confirmation collaborating your info in Wikipedea.

I also checked the Prius batteries in ebay.de, just one entry for a used unit, almost €1,900. For this price I can buy a couple of C5s, so I think I'll give these a miss.

There is one point you may be able to help me with, and that is with my RC LiPo packs I need a balancer to charge them. Is this also the case when using individual LiFe cells as a pack?

That is why I said "when you find a good auction" ;-) My friends have bought 5 or 6 packs so far at £400 average. Just remember that there are also the newer packs from last 2 years or so, much bigger and more expensive of course.

As for the LiFe and balancer short answer is yes, it's also better to have one. If I don't forget I will ask my friend if there are any major differences beside the voltage in LiFe and LiPO balancing.

Now I understand where you got the odd voltages from!

My current LiFePO4 batteries are great and top voltage I see is 14.4v. My charger lets them drop to 13.6 volts on float and tops up to 14.4v so no problems using them on a nominal 12v system.

As for the balancing of the cells you have to watch out for them limiting the current the cells can deliver. I've seen starting currents of 90 amps when moving off on a hill even when pedalling, best to check those set ups before you buy. The batteries I have are built for traction systems so have no electronics on them at all to avoid this. So I would say the balancing isn't required on this type of cell.

I will say I'm not going back to Lead Acid batteries - way too heavy on the C5. I now have 40ah at 6kg, much easier on the legs than my old 19kg Leisure battery.

Well, balancing is also not required on LiPO and if the cells are selected properly (so all are coming from the same bin therefore have very similar characteristics) they can last long, if they are chosen just randomly then it's a different story. And besides the charging phase balancing may be also used during normal use and if one cell goes down balancer will react accordingly so this cell will not cause damage to the others. So you are correct it is not required, just helpful precaution and battery life extension

Hi Rusala,

without wanting to start a war, I've been in the model aircraft scene for over 30 years, and one thing I learned a long time ago is that LiPo batteries are very dangerous when not handled or charged correctly. All my 3s packs (bought as sealed packs) are wired for balancers. It just needs one cell to go down, and without a balanced charger can lead to disastrous effects. The RC forums and the IN are full of such cases, and in most cases it's 2S and 3S (S or S/P) packs that cause the problems. Up till now, touch wood, I've had no major problems. LiPos don't need to be balanced by every charge, but they must be balance charged very regularly. So it's simpler just to balance change them. This may or may not be the case with LiFe, but it's something I need to know, hence the reason for asking.

Even though I always buy complete packs I've never had one pack that hasn't suffered from a dropout before it should. After doctoring, these I relegate to, and used as, 2S packs instead of buying 2Ss. I must admit things have improved over the years, but caution is still the main priority.

The same has often cropped up with lead-gel batteries supplied by the same vendor, for use in e-scooters and bikes. One of the 2/3 batteries drops out a lot sooner than the other(s). I also mentioned this in a prior post to this theme.

I have no experience with LiFe, but I need lighter batteries for a project, this is why I'm on the lookout for information to assist in purchasing some.

You are right, they shouldn't be fully charged to prolong the batteries life.
I found the site that quotes 4.2 volts for a fully charged LiFe.
http://batteryuniversity.com/learn/article/charging_lithium_ion_batteries
The max voltage for LiPo's is also quoted as 4.2 volts, but my charger wont deliver such a high voltage.

Hi Karl

You are absoluteley correct and I DID say that it's better to have balancer. But as a matter of fact there are plenty of aplication where balancing is not used. Likely it's just because its cheaper this way :/ And if you have very similar cells you can go without balancing for a long time however you are correct also - it is better to balance them at least after some charging cycles.
I just wanted to point to jockywilson11 that when his not using balancer he won't necessarily blow up on his next ride unless his cells are not matching very well. As few examples: there were (i don't know if this is still popular) 2 cell packs used in many cameras and I did not see any balancing there, also some ebikes using LiPO do not have balancer. Thing depends also on an application, in RC and partly in EVs the currents are much higher and thus more danger of destroying the cell. So not having balancer in camera may be OK especially if they are good quality and maching but i would also recommend to have a balancer in EV and in RC definitely as you guys are crazy and draining million amps out of those poor small cells :-P :]

Out of practice - packs build from Prius cells are still balanced on every cell after many charges and we did check that few times in case a balancing would be needed. It is not convenient at all but as we already agreed balancing at least from time to time is a good thing we did check. So if the cells are still well balanced you can still go on without balancer during charging. However original Prius pack has a wiring for balancing so even though those are very good cells when they are used extensively for few years they will be imbalanced for sure.

Everybody here that is not experienced in Lithium batteries please in the name of safety forget what I said and INSTALL BALANCER :D As Karl said caution is still the main priority!

As for LiFe i did not mentioned before that there is one more advantage of those. They do not experience exothermic reaction as LiPO dose. Chemistry behind the battery is a bit different then in LiPO and makes LiFe much safer. My friend is in the meeting now but so when he's finished I will ask him about balancing recommendations on LiFe.

Hi again

I've talked to my friend about LiFe balancing and basically he confirmed what I've said before. There are number of different solutions for balancing but essentially no differences between LiPO and LiFe other than the voltage (max 4.2V and 3.6V respectively). LiFe are safer so it's unlikely for them to blow up however battery may still be damaged if one cell goes down. He pointed me few situations when "simple" balancing circuits won't prevent failure however it's better to have at least such one than nothing. And it seems that balancing in LiPO is more common than I though as my assumption was that balancing circuits are more often outside the pack but it turns out it's the other way.

Hi Rusala,

as opposed to LiPos I've never heard of any dangerous cases with LiFe batteries, this was the reason I was asking. Up till this discussion I've done no research into LiFe batteries, so I'm in the dark at the moment, plus the IN is of no help.](*,) ](*,) In my searching I find a case of 50/50 when referring to the need of balancing with LiFes. There is a 12v battery pack being offered by the company that Jocky recommended where they quote the cells have been closely matched, for this reason it's not fitted with a balancer. So I assume that LiFes are not so critical as LiPos. From what I've read you need to be really stupid before you can cause a cell to explode, plus there's no danger of fire as with LiPos.

I was looking at this 12v battery as the idea of having the cost and time to link single cells up, make a container the secure the cells and to transport them will raise the cost to almost that of a single unit.

Just to make matters worse it turns out there is more than one type of LiFe battery, and trying to find out what the differences are is turning out to be a real pain in the neck. With my luck, just as I think I've got it cracked a new type will crop up.
Or should I just give up and wait for the Graphene supercapacitors, super light, and supposedly cheaper than batteries. Oh heck! maybe they need balancing.:-" :-"

To make the long story short - when we're talking about LiFe and you are just concerned about safety you can get away without balancing during use and maybe even charging and still be pretty safe. However if you would like to ensure long flawless battery life it's better to use balancer.

As for the new types of batteries, not so long ago I read few articles about studies or even early stage of implementation of a type that uses carbon in both anode and cathode and was supposed to be produced on a same production line as LiPO and have some great characteristics. It sounded interesting and a bit more legit then other such news but who knows...

[quote=jockywilson11;5206] I will say I'm not going back to Lead Acid batteries - way too heavy on the C5. I now have 40ah at 6kg, much easier on the legs than my old 19kg Leisure battery. [/quote] Same here, once you have used these batteries you never want to use lead acids again

Hey guys,

I am willing to overvoltage the current motor (DCPM motor Class F, 12V, 29A, 250W, 3300rpm) .. to (18V) .. so as I can get more power ..

My question is: How to calculate the new power?

I think If I can calculate the new power and measure the new RPM, I can get the new torque .. That's why I am asking about the new power ..

Thanks in advance !

I think you may use the Kv constant. Assuming that for your motor it is 3300rpm/12V=275 at 18V you should theoretically get 18V*275rpm/V=4950rmp. That is without load. However I'm not sure how exactly it affects the torque. I would have to ask few friends who are much more familiar with those stuff.

Thanks Rusala for your useful reply .. I am waiting for your checking with your friends .. Thanks alot !!

[size=6][color=darkblue]This seems like something I may look into.
If I wanted to use two of these how would I do it and what are the effects on motor, control box, brakes etc?
Would it increase range or power? (or both)[/color][/size]

Would it be possible to use 4 of these?

http://www.everything-ev.com/index.php?main_page=product_info&cPath=65_128_135&products_id=497

And if so, how complicated?

All of these was already described. Generally if you connect two batteries in parallel you almost double the range. Connecting them in series will increase the voltage and thus the power but it is unlikely that the motor and control box would withstand it without problems. Check other topics concerning 24V modifications.

Those LiFe batteries from your second post are nice idea. They are safer and lighter the the Pb. Just remember to get a proper charger.

The cells listed in your link are OK, but I think you'll find these to be a lot easier on your pocket.

http://www.ev-power.eu/Sinopoly-40Ah-300Ah/SP-LFP40AHA-Lithium-Cell-LiFePO4-3-2V-40Ah.html?cur=1

4 cells cost only £143 (includes the 21% VAT) as opposoed to yours at £260. Plus these are somewhat smaller and lighter.

The only problem is, I have no idea what they charge for tranport to the UK.

They look good.
I wonder, is there sources of instruction diagrams/manuals for stacking such batteries available?
I have searched for instructions on such as well as general electric motors and control boxes but I have been confused by the info out there.
The resources section here is good but for a complete newbie it seems all rather expert.

I would like to study lots material so to avoid asking hundreds of question here but where to start.

Lots to learn I think :-)

If you're completely new to electricity I would suggest to start from these just to grasp a concept and basic terms:

http://www.dummies.com/how-to/content/electronic-basics-electrical-current.html
http://www.dummies.com/how-to/content/electronics-basics-electrical-voltage.html
http://www.dummies.com/how-to/content/electronics-basics-electrical-power.html
http://www.dummies.com/how-to/content/electronics-basics-electric-charge.html
http://www.dummies.com/how-to/content/basic-electronic-components-and-what-they-do.html
http://www.dummies.com/how-to/content/electronics-schematics-commonly-used-symbols-and-l.html
http://www.dummies.com/how-to/content/how-to-build-a-simple-electronic-circuit.html
http://www.dummies.com/how-to/content/how-to-measure-current-on-an-electronic-circuit.html
http://www.dummies.com/how-to/content/how-to-measure-voltage-on-an-electronic-circuit.html
http://www.dummies.com/how-to/content/measuring-stuff-with-a-multimeter.html

I've just picked some randomly and for sure there are many more. It's best to first know what happens with component parameters when as batteries, resistors, capacitors and so on when you connect them in series or parallel and after you have some basics then try to search something on electric motors. There are many different kinds out there so it's rather hard to explain everything at once.

Brilliant mate :-)
Many thanks :-)