[Flamingibis1!]

I have an 81 VW rabbit with 16 6v golf cart batteries. 8 batteries in the engine compartment and 8 in the trunk. With new batteries it has a range of 40 miles. It is time to change the batteries. Is there any more modern battery that will be a direct replacement that I could double the range? question 1: is it possible? Is it economically feasible? I guess I am asking if there is anyway of getting twice the range for twice the cost of what the replacement for lead-acid batteries would be?

 

[floydr]

96v nominal battery pack. How many volts can your controller handle? if I were making a battery pack for a car 2.6 of these modules in series gives you 96.2V nominal LG 36v 7.9kWh 10s EV Module - $100/kWh 82Lbs each module so around 220 lbs for the battery pack. and you get up to a 20 kWh battery. you would need to add a BMS. don't know if you want to go to all that work. cost would be ~$2400 + the Bms. less than 16 Trojan T-125 . course building a lithium battery pack this big is not for all people. Also would need a new charger. The weight saving alone is 6-8 hundred lbs, 300-350 kgs. so yes it is possible to extend range double or more. depends on how much work you are willing to do. if your controller could handle the volts 3 complete packs in series is 111v nominal 126V max for a hair under 24kWh capacity. Probably less since these are used modules. You could double the modules to 6 and really extend range. the modules would need capacity testing to be sure how much capacity you have.
later floyd

 

[john61ct]

LFP

4 in series per 12V increment.

Double the usable Ah for same weight and volume. Or same Ah half the weight and volume.

Will last 10x as long as lead easy, more if coddled. Much faster charge rate when needed, no need to keep at high SoC.

Top quality makers are Winston, CALB, GBS, Sinopoly and CATL

 

[reiderM]

4 Tesla modules would match your pack voltage and give you probably more than double of the range you're currently getting. Total cost about $5000, including the BMS and the modules.

 

[piotrsko]

And you maybe don't need a new charger. My volt pack directly replaced the FLA trojan pack at nominal voltage. Peak charge at bubble was under the max allowed for the lipo cells so I took a gamble for the last 8 years.

Yeah I know, heresy.

 

[DaviLightning]

if your controller could handle the volts 3 complete packs in series is 111v nominal 126V max for a hair under 24kWh capacity.
later floyd

I know I'm the new guy around here, but this doesn't sound right. The 7.9 kWh doesn't triple when wired in series does it? The voltage adds up, but the kWh would remain 7.9 if wired in series, no?

 

[OR-Carl]

The 7.9 kWh doesn't triple when wired in series does it?

It does. You are maybe confusing the energy (kwh) with the amp-hour rating. Those 36v and 7.9 kwh modules would have about 220 AH. In series the voltages would add, but the AH stays the same. In parallel the voltage stays the same and the AH adds up. Either way you get the same energy

(36*3) v * 220 AH = 23.7 kwh = 36 v * (220*3 AH)

 

[DaviLightning]

It does. You are maybe confusing the energy (kwh) with the amp-hour rating. Those 36v and 7.9 kwh modules would have about 220 AH. In series the voltages would add, but the AH stays the same. In parallel the voltage stays the same and the AH adds up. Either way you get the same energy

(36*3) v * 220 AH = 23.7 kwh = 36 v * (220*3 AH)

Ah, okay, thanks for the clarification. I was confusing the two.