# Trojan overdrive AGM 31 opinions?



## Ace_bridger (Nov 22, 2011)

I too am currently trying to specify a pack for my Golf.

I have to ask, have you considered lithium? Although I am hoping to put together a lead pack myself lithium are far better and considerably cheaper /mile over life.

Price is reducing too...slowly.

Good luck 

Ace


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## piotrsko (Dec 9, 2007)

sounds like you may need to do a amp/hour to dollar comparison. OTOH I also think you may want to talk to a Trojan distributor about his products, then get hard numbers from odyessy or other major competitors. The CCA ratings alone say that these batteries aren't true deep cycle with massive plates. My 225's weigh 78 lbs ea, rated at 130 ah (?) 20 hr and were $160 ea.


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## DanGT86 (Jan 1, 2011)

Ace, Yes I have thought about lithium. Actually I don't really ever stop thinking about lithium. I am planning to sell the car when I fix it up and Lithium would make the total price too high. Used ev conversions don't sell for much more than about $8k around me. My next EV will have lithium but it will be a keeper for me. 

I Emailed Trojan and got a quick response. I got some better AH data

Trojan Overdrive 31AGM 70lbs 
100amps for 25min to 100%DOD
@25 min 42 AH 
@2 hour 65 AH 
@5 hour 82 AH 
@10 hour 92 AH
@20 hour102AH

Odyssey 1700 60lb 
110 amps for 25min
@25 min 46 AH
@2 hour 57 AH
@5 hour 62 AH
@10 hour 65 AH
@20 hour 68 AH

Odyssey 2150 71lbs
140 amps for 25min
@25 min 55 AH
@2 hour 75 AH
@5 hour 85 AH
@10 hour 92 AH
@20 hour 99 AH

Seems like the Odysseys take the win at the 1hour rate and lower. If my thinking is right and I pull 110amps at 50mph for 25min that should be around 20 miles. That seems reasonable, although a very rough estimate. Looks like I could use the 1700s and have roughly the same range at 730lbs total pack weight. They are also 2 inches shorter than the Group 31 Trojans. Question is: how will they hold up?


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## madmike8 (Jun 16, 2011)

What kinda pricing can you find on the 2150's? A quick look by me seems to be around $350. Then pricing 4 (12v) 60ah TS or CALBs seem about the same price. I noticed that evassemble is selling 32 10ah headways pack @ about 22.15 per cell shipped on ebay. So, that would basically be about $354 per 12v 40ah pack with the ability to expand as needed.

I just can't talk myself into lead...


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## DanGT86 (Jan 1, 2011)

I found a battery distributor that priced them:
2150 $280
1700 $200
Trojan AGM $180

My understanding of lithium is that I would want qty. 45 100ah TS or CALB cells so I could peak at 500 amps without being too hard on them.

45 cells at $130 each puts me at $5800 give or take shipping sale prices etc. That doesn't include battery management on my $6000 pack. 

I can also drive a few hours to buy the lead face to face with warranty. The lithium is still kinda tricky to get by comparison. I hear you on the cost per year/mile thing but its just too much $ for a car I wont keep that long.


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## madmike8 (Jun 16, 2011)

From my understanding the 60ah CALBs have a 4c 240a continues rating and a 12c 720a burst rating. Even if your hard on them and reduce their life in half they are still better than lead.

You don't have to have a bms, but it can give you some peace of mind.


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## Yabert (Feb 7, 2010)

DanGT86 said:


> My understanding of lithium is that I would want qty. 45 100ah TS or CALB cells so I could peak at 500 amps without being too hard on them.



Here my understanding of lithium cells VS lead.

ODYSSEY PC 2150: 144v = 3360$, 67.2Ah @ 1hr rate, capable of more than 500A (controller limit?), 934 lbs, need 157 liter of space, few hundred recharge cycles.

Calb 70Ah: 144v (45 cells) = 4140$, 70Ah @ 1hr rate, capable of more than 500A (700A ≤10s), 248 lbs, need 63 liter of space, 2000-3000 recharge cycles.


So, lead choise is: 3.7 x more weight, 2.5 x more space, for only 20% economy..... and base on 2000 cycles, they will cost 300-400% more.
I think it's why many people say than lead are obsolete.

But it's your choise, I can understand than lead is attractive because they seem simple and cost less.


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## DanGT86 (Jan 1, 2011)

I get it but good deal or not the total cost is a huge factor in this scenario. I plan on selling the car within the year and unless I can find a buyer that would appreciate the lithium's value, I would just be giving away a more expensive pack. My charger would also have to be replaced so that would incur more costs yet. If the lead gets the next buyer a couple of years EV experience then they can upgrade to lithium. 

I guess my lead acid question is this: If I have 2 batteries with drastically different 20hr rates but the same 1 hour rate, and I always discharge them around the 1 hour rate, will they perform basically the same? Is it really that simple or am I overlooking something.


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## Sunking (Aug 10, 2009)

DanGT86 said:


> Trojan OverDrive AGM31
> 12v
> res cap @25A 180min
> 84 AH 5hr rate
> ...


Seeing a CCA rating would run me off because that tells me right away they are not deep cycle batteries and would not last long. That tells mew they are a cranking/starting battery. No true deep cycle battery will have a CCA or MCA rating. If they did it would be a very low rating. Look at the T-105, T-875, and T-1275 rating on their deep cycle line. No CCA ratings.


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## piotrsko (Dec 9, 2007)

DanGT86 said:


> I guess my lead acid question is this: If I have 2 batteries with drastically different 20hr rates but the same 1 hour rate, and I always discharge them around the 1 hour rate, will they perform basically the same? Is it really that simple or am I overlooking something.


IMHO they will discharge at different rates with the smaller battery going flat first


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