# Trojan Batteries for Kandi Coco



## rkarl89203 (Aug 15, 2011)

Hi folks....

Question about my Kandi Coco's Trojan Batteries....

they are 105ah with the semiauto battery watering system (caps connect to watering system ).....I fill them once a month.

They are almost 5 years old.....5 of them out of 6....

How long do these last normally...still have 35 mile range in my Coco after controller reprogram last winter but now I am getting error 2s and I notice flaking and some leakage under battery rack...?

any ideas on this?


----------



## Sunking (Aug 10, 2009)

You are lucky to gotten this far because Trojan FLA batteries are a 2 year battery.


----------



## rkarl89203 (Aug 15, 2011)

I didn't even realize that.

What I am curious about is whether that can cause the Error 2s I am getting.

Thanks for the reply.


----------



## athomas03 (Jul 13, 2011)

Sunking said:


> You are lucky to gotten this far because Trojan FLA batteries are a 2 year battery.


I disagree, they easily go 4-5 years with proper care.

As far as the errors, don't know.


----------



## dragonsgate (May 19, 2012)

Sunking said:


> You are lucky to gotten this far because Trojan FLA batteries are a 2 year battery.


My first pack was a dozen Exide 12 volt deep cycle. I drug them down pretty bad several times and they went out in with in 18 months. I have been running this pack of eighteen T875 eight volt batteries for right at three years eight months now. This is my third pack of Trojan T875s in fourteen years. They are still getting me around fine with no drop in performance. I have noticed a very slight drop lately in voltage at the end of a drive. Usually after a 20 mile drive I get a reading of 146 on my multi meter immediately after parking in the garage. Lately it has been showing 145.5 after the same distance. I don’t think I have ever gone over 30% dod. All I do is keep the water up keep the tops of the batteries and posts clean and equalize every tenth charge. I am not promoting lead batteries over any others just saying depending on the batteries and how well one takes care of them has a lot to do with how long they last. One set of Trojans I saw would be a good testimonial for the company. A friend of mine owns an RV park and cottages for rent. She had a golf cart with six Trojan T105 batteries. One day she called me and asked if I would come over and look at her golf cart. She said the batteries were a year old and the cart would not go as fast as when the batts were new. I lifted the seat to look at the batts and found a quarter inch of dirt and that fuzzy greenish corrosion covering most of the post connections. I checked the water and was not surprised to find all cells low on water and several dry. I cleaned everything up and got the cells filled and charged and scolded her for mistreating things. The cart ran fine. To make this short she drove that cart mistreating those batteries for five years with me coming over to maintenance them and scold every spring before they finally were beyond repair.


----------



## rkarl89203 (Aug 15, 2011)

*UPDATE My T-1275 plus Trojan batteries*

After much analysis, and an assist from my friend David in Cedar Rapids with a controller update, I checked all my batteries....

Every single one reads 12.9V.....The INTERESTING part is that, doing the specific gravity on each cells electrolyte, I came up with interesting readings.

The first four batteries I checked were all equal on the checks, specific gravity-wise. *The fifth battery was weird*, though. the first 3 cells were equal to all the others I had checked...the FOURTH cell was way down, and the electrolyte was so dark that it was hard to even read the indicator. The last two were marginal.

So, I checked the final battery in my 6-pack on my vehicle. The first two cells measured almost nothing. *The third cell MAXED out the indicator!*
*Didn't even check the last three cells.*

Judging by these results, I think it is fair to say that I need a minimum of two new batteries. As the other 2 batteries in that bank are the same age (over 4 years) and ALL are creating a grey/yellow corrosion under the battery rack, I think maybe replace all the back 4?

Any opinions on this?


----------



## piotrsko (Dec 9, 2007)

my experience says if the bad 4 are at the negative end of the string, replace them and switch position on the others so the the more negative positions are at the more positive location. IE the most negative becomes the most positive.


----------



## rkarl89203 (Aug 15, 2011)

Pricing them....looks like high $160 to $220 each.
Looking for a good suppler here in Northern Illinois.


----------



## dragonsgate (May 19, 2012)

rkarl89203 said:


> Pricing them....looks like high $160 to $220 each.
> Looking for a good suppler here in Northern Illinois.


If you put new lead batteries with old you are wasting money. It doesn’t matter how good you think a couple of batteries are if you hook new batteries to the old batteries they will drag the new ones down to their level. If you are running a 36 volt system then it would not cost that much to do lithium. If you insist on sticking with lead then you are going to have to bite the bullet somewhere and come up with some money for some good quality batteries. If you get to cheap then it will wind up costing more in the long run. At $200 a pop for a 6volt battery x 6 =$1200. You could get eleven 100amp lithiums for close to the same amount. This is where Lithium would truly windup costing less in the long run.


----------



## rkarl89203 (Aug 15, 2011)

I have a 72v ac drive system.
I haven't decided whether to replace 2 or 4 batteries.
As far as mixing old and new I had to replace one in front of the car after an accident and its done just fine since then.
My post was about availability.


----------



## Siwastaja (Aug 1, 2012)

Update to lithium at this point. 5 years is exceptionally good and you need to replace all the cells anyway unless you want to spend even more money.

Lead is the most expensive in the long run and you probably want to save money, right?

LiFePO4 is the cheapest battery chemistry available now (total ownership costs in long run).

Lead only makes sense when you want something for quick testing with a bit lower upfront cost.

Similarly sized lithium pack runs typically 20-40% higher upfront cost but 40-80% lower long-term cost. Lithium pays itself back typically in 3-4 years -- when you find yourself getting a new lead pack and at that point you are much over from the original price if you had bought LiFePO4 in the beginning.

However, many people increase their pack capacity while upgrading because it's possible from the weight viewpoint. In that case, it of course costs more. This leads to unfair comparisons. But you don't need to do that, you can get a similarly sized pack which gives you the same range as the original lead pack if you want to. This is a real money saver.

Do an informed decision.


----------



## rkarl89203 (Aug 15, 2011)

The manufacturer of my vehicle says that lithium cells cannot be reliably or safely charged with the installed onboard charger.
Also....lithium cells can overheat and sometimes require water cooling. I cant even begin to think of how I could do that with the available space.
thanks for the reply though.
I actually like the performance I get from the lead-acid cells.


----------



## dragonsgate (May 19, 2012)

rkarl89203 said:


> The manufacturer of my vehicle says that lithium cells cannot be reliably or safely charged with the installed onboard charger.
> Also....lithium cells can overheat and sometimes require water cooling. I cant even begin to think of how I could do that with the available space.
> thanks for the reply though.
> I actually like the performance I get from the lead-acid cells.


I can respect your decision to stay with lead for what ever reason but I must reiterate that to add new lead batteries with older ones in not a good thing to do. Even if you are getting good readings on one or more of the older batteries they are going to start deteriorating at a faster rate than the newer ones thus shortening the potential life span of the newer batteries and the over all pack.


----------



## PStechPaul (May 1, 2012)

If you want to try a low cost option you can get 100 Ah 12V deep cycle batteries from Walmart for about $77 each. 
http://www.walmart.com/ip/EverStart-27DC-6-Marine-Battery/16795212

So you could replace your entire 20 kWh pack for $460. Even if you get only 300 cycles and one year of use it will cost you only $1.50 per cycle which will only about double the cost of the energy you pay for from the grid. For the equivalent in LiFePO4 (10 kWh) you will spend about $3500 and probably $1000 on top of that for a BMS and charger. YMMV. 

_*All right, who is the coward who is giving me bad reputation points for trying to offer what I think is a reasonable solution to the OP's needs? If you feel so strongly that this is bad advice, why don't you reply with specific reasons why you feel that way, and thus actually help?*_


----------



## Siwastaja (Aug 1, 2012)

PStechPaul said:


> If you want to try a low cost option you can get 100 Ah 12V deep cycle batteries from Walmart for about $77 each.
> http://www.walmart.com/ip/EverStart-27DC-6-Marine-Battery/16795212
> 
> So you could replace your entire 20 kWh pack for $460. Even if you get only 300 cycles and one year of use it will cost you only $1.50 per cycle


6 * $77.97 = $467.82
6 * 12V * 50Ah = 3600 Wh. Even if you calculate with the nameplate values, it will be 8280 Wh, not 20 kWh. So you just calculated wrong. It happens. Usually, when you get an extraordinary result showing something against the reality, double-check the numbers.

$0.13 / Wh upfront cost ($467.82)
Let's assume 300 cycles. $1.55 per cycle. You were close.

Similarly performing, similar capacity LiFePO4 pack is 72V40Ah, for example, http://www.ev-power.eu/Sinopoly-40Ah-200Ah/SP-LFP40AHA-Lithium-Cell-LiFePO4-3-2V-40Ah.html . 

23 * 3.2V * 40 Ah = 2944 Wh.
Upfront cost $1200. Let's assume 3000 cycles. $0.40 per cycle.

You may be able to find lithium for cheaper in the States.

The type of lithium cells shown have a good track record in EV usage and they deliver more than their rated capacity for years and years. The type of lead acid shown is a random unknown brand and those are known to suck hard in the EV application. They are not designed for that. They are designed for much lower currents and slower cycling. Known good "EV-grade" lead acid batteries are more expensive.



> _*All right, who is the coward who is giving me bad reputation points for trying to offer what I think is a reasonable solution to the OP's needs? If you feel so strongly that this is bad advice, why don't you reply with specific reasons why you feel that way, and thus actually help?*_


I reported your post with the following message:

"Hi, dear administration.

I'm reporting this post just to get your attention while there's nothing wrong with the post. Sorry for that.

I think it's now the time for you to take the critique on the reputation system seriously. The problem of anonymous bullying through your totally flawed and broken system has been reported many times, still you do not even comment on the matter.

Please either disable the reputation system or provide a good explanation why not."

My personal guess is that someone else also noticed your calculation error. But that could have been publicly corrected with very little effort. If nothing else, just stating that "You calculated wrong".


----------



## PStechPaul (May 1, 2012)

Thanks for the double check of ratings. But here is screenshot of the page from Walmart where it states that this battery is 109 Ah:










I was surprised at this rating, because the larger size 29DC battery which is about $99 and weighs 10 pounds more is 115 Ah:
http://www.walmart.com/ip/EverStart-Maxx-Group-Size-29-Marine-Battery/20531539

There is also a size 24DC battery for $68 which is 44.8 lb and has 101 Ah rating:
http://www.walmart.com/ip/EverStart-Group-Size-24DC-Marine-Battery/20531540

I think I will get one of those for my electric tractor. If it works well I might get another one for a 24V system and 2400 Wh which should be enough to get the full 2HP from my motor if needed, and 600W for normal driving at C/4 where even with Peukert and 70% DOD I could get about 2 hours run time.

For the OP, Walmart also has 6V 200Ah SLA batteries for $216:
http://www.walmart.com/ip/Schumache...Schumacher-Electric-6V-200AH-Battery/25955621

Also, that seems like a good price on the Sinoply LiFePO4 batteries. About $0.44/Wh. Of course, shipping costs and possibly taxes and tariffs might have to be added. For the batteries at Walmart, I would pay 6% sales tax.


----------



## rkarl89203 (Aug 15, 2011)

Ok folks...

Thanks for all the advice....didn't mean to start the internecine battles here though.

I have decided to change the two Trojan batteries with new ones of the same type.

I will check the walmart deep.cycles too.....


----------



## Siwastaja (Aug 1, 2012)

PStechPaul said:


> Thanks for the double check of ratings. But here is screenshot of the page from Walmart where it states that this battery is 109 Ah:


Hi,

You should learn how lead acid works.

1-hour or 45-minute rating is typically half of the 20-hour rating, which is the one cited in the spec sheet. You may want to add your DOD% on the top of that. From a 115 Ah lead acid battery, 50 Ah out is quite good in an EV application. With cheap general purpose batteries, you can expect less than that, especially after a year or two of usage.

This is called the Peukert effect and it is why lead totally sucks in fast discharge applications such as EV's. That's why it's not used unless nothing else is available. For example, NiCd has double the energy density in reality and was used in commercial EV's before the era of NiMH. OTOH, lead is just fine in stationary, large pack (slow discharge) applications.


----------



## rkarl89203 (Aug 15, 2011)

Oy.

Look folks....I made up my mind...the car came with LA batteries....and that's what I am installing.

Thanks for the help.


----------



## Siwastaja (Aug 1, 2012)

That might be a good idea even if the long run cost is higher because it may happen that the li-ion price has gone down after 3-5 years when you need to replace the pack again. 

Just replace all the batteries at the same time with ones from the same batch and initially charge them separately to 14.5 volts with a lead acid charger. Make sure they are fully charged before installing. (This is called top balancing and it's the only way with lead acid.)


----------



## ga2500ev (Apr 20, 2008)

Siwastaja said:


> 6 * $77.97 = $467.82
> 6 * 12V * 50Ah = 3600 Wh. Even if you calculate with the nameplate values, it will be 8280 Wh, not 20 kWh. So you just calculated wrong. It happens. Usually, when you get an extraordinary result showing something against the reality, double-check the numbers.
> 
> $0.13 / Wh upfront cost ($467.82)
> ...


I have a question here. The 40 AHr cells you quote state a 3C continuous with a 5C pulse current draw. In a typical configuration, would not both of these ratings be exceeded on a regular basis (120 A continuous, 200A max)?

While heavy current draws will absolutely kill the range on the lead acid pack due to Peukert, those heavy draws are allowable.

The issues above are why I've been interested in Ziggy's Lead/Lithium hybrid pack with parallel strings of Lead and Lithium. From his measurements, the Lithium lightens the current draw on the lead, extending its range, while the lead buffers the lithium from being over-discharged. 

ga2500ev


----------



## Siwastaja (Aug 1, 2012)

ga2500ev said:


> I have a question here. The 40 AHr cells you quote state a 3C continuous with a 5C pulse current draw. In a typical configuration, would not both of these ratings be exceeded on a regular basis (120 A continuous, 200A max)?


Many think that Chinese LiFePO4 cell manufacturers actually underrate their cells. Look at all the people drawing 10C from the grey CALB cells, and recently, Sinopoly was tested to have similar current capability.



> While heavy current draws will absolutely kill the range on the lead acid pack due to Peukert, those heavy draws are allowable.


There's a "hard" limit too... Lead acid will also heat up. Or just be totally unusable. As we all know, half-an-hour rating of lead already makes the capacity so small that you can barely do anything with it. And half-an-hour is just 2C.

LiFePO4 is just fine when discharged fully in 15 minutes. In large packs, you may need to think about cooling the cells, otherwise it may get a bit hot in the middle.

OTOH, the current ratings manufacturer give are at temperature of 25 deg C. As the cells heat up, their efficiency improves and less heat is produced and the allowable C rating goes up.

All in all, if the lead pack worked practically at all, it was not used at more than 2-3C on average, which is fine for lithium, too.




> The issues above are why I've been interested in Ziggy's Lead/Lithium hybrid pack with parallel strings of Lead and Lithium.


Well, just increasing the pack size has the same effect on current rating, it can be all lithium.

But Ziggy's "hybrid" makes a lot of sense in two ways:

1) He already has the lead pack, so he can get more range and power for the same money instead of just ditching the lead pack. Once the lead starts to die, he can just install new lithium cells in parallel.

2) The paralleled lithium pack actually improves the lead pack's usable Ah rating (due to Peukert); so you get more Ah out from the lead pack than you normally do, increasing both it's energy density and value. Again, this is not thanks to lithium itself; you get the same effect by getting a larger lead pack. But then, weight is usually a limiting factor, so lithium makes lead better without getting into weight problems.


----------



## ga2500ev (Apr 20, 2008)

ga2500ev said:


> I have a question here. The 40 AHr cells you quote state a 3C continuous with a 5C pulse current draw. In a typical configuration, would not both of these ratings be exceeded on a regular basis (120 A continuous, 200A max)?
> 
> While heavy current draws will absolutely kill the range on the lead acid pack due to Peukert, those heavy draws are allowable.
> 
> ...





Siwastaja said:


> Many think that Chinese LiFePO4 cell manufacturers actually underrate their cells. Look at all the people drawing 10C from the grey CALB cells, and recently, Sinopoly was tested to have similar current capability.


Well this is encouraging. I could wrap my mind around a pack with 40-60 AHr cells in terms of cost. Even with the lower TOC, the thought of spending north of $5K USD for 100+ AHr cells



> There's a "hard" limit too... Lead acid will also heat up. Or just be totally unusable. As we all know, half-an-hour rating of lead already makes the capacity so small that you can barely do anything with it. And half-an-hour is just 2C.


No disagreement with this. The pack will sag under heavy load, and will empty quickly. I'm not trying to dismiss all of lead's numerous faults. However, there is merit in being able to capitalize 8 12V 109 AHr (nominal C/20) batteries for around $700 when the capital costs for even 30 of the 40 Ahr lifepo4's will be at least double that. And until your statement above, even that cost wasn't terribly feasible.

more later.

ga2500ev


----------



## ga2500ev (Apr 20, 2008)

Siwastaja said:


> All in all, if the lead pack worked practically at all, it was not used at more than 2-3C on average, which is fine for lithium, too.


But the nominal capacities on the batteries vs. the corresponding cells are different. 109 AHr/40 AHr = 2.72. So the 2-3C average is based on the C rating on the plate. So in theory 3C on the lead is 327 amps vs. 3C on the lithium is 120 amps.

The real problem for me is trying to compare the ratings on the plates vs. the ratings in real life. It's a crap shoot.



> Well, just increasing the pack size has the same effect on current rating, it can be all lithium.


But there's a cost differential to do so. Also, using the plate ratings, it's not possible to even start with a smaller lithium pack, then add to it later.

I know that folks get frustrated with me when I talk about the cost of capitalization. But it's really important to discuss the cost of investment when there's no guarantee of success and limited funds. I find that most pack discussion focus on the final results instead of the proof of concept. I too would have a 320V 200 AHr AC setup if I had unlimited funds (yes I am over-exaggerating). But if the objective is show that it's possible to get a vehicle around the block as cheaply as possible, then a handful of 12V deep cycle lead acids look pretty tempting even if the range is awful and they need to be replaced in a year.

For example I have access to refurb half U1 12V 35 Ah SLA wheelchair batteries at $25 USD for as many as I want. I can get around the block for about $400 (96V, 70 AHr). There is simply no lithium solution that can match [email protected] for $50. Yes they are heavy. Yes they will drain in nothing flat. Yes, they would need to be replaced in short order. But nothing lithium can touch the capital cost. If anyone can suggest it, I'll be happy to buy.



> But Ziggy's "hybrid" makes a lot of sense in two ways:
> 
> 1) He already has the lead pack, so he can get more range and power for the same money instead of just ditching the lead pack. Once the lead starts to die, he can just install new lithium cells in parallel.


This point is not negated even for someone who doesn't yet have a pack, but has the desire to get going. Start with a lead acid starter pack (cheap). Support with a small lithium pack (not as cheap, but can still be small and can be added later), upgrade lithium in increments as funds/time allows. Also there's still the crucial point that the lead acid pack has the ability at all times to buffer whatever lithium is connected so that it doesn't overdischarge.



> 2) The paralleled lithium pack actually improves the lead pack's usable Ah rating (due to Peukert); so you get more Ah out from the lead pack than you normally do, increasing both it's energy density and value. Again, this is not thanks to lithium itself; you get the same effect by getting a larger lead pack. But then, weight is usually a limiting factor, so lithium makes lead better without getting into weight problems.


BINGO! In short you combine two smaller cheaper packs to get a combined pack with better characteristics than either of the individual packs, or with double packs of a single chemistry. Each side supports the other side's weaknesses.

I checked out the EV album. I could not find a single car conversion that used 40 Ah lithium for the traction pack. Does anyone have proof that it can be done? 

ga2500ev


----------



## rkarl89203 (Aug 15, 2011)

Well, was just about ready to purchase my batteries when I became aware that Kandi Technologies will be no longer importing the KD08E Kandi Coco to the USA. The lack of the EV parts page on KandiUsa's website tipped me off.

Hmmm.....called and confirmed this with parts dept. KandiUsa....Emailed sales rep there but got no answer. usually not a good sign lol....

SO...I appear to be on my own.....but this DOES explain the lack of parts availability, etc.

What would YOU do?


----------

