# Car v cart batts?

Regarding flooded cell batts, I hear the Trojan T105 is popular. But costs \$125 and up. But I can get any old Exide 12V car batt for \$65. So what am I missing?

you are missing AMP hours

[QUOTE=CO BOB;2835]Regarding flooded cell batts, I hear the Trojan T105 is popular. But costs \$125 and up. But I can get any old Exide 12V car batt for \$65. So what am I missing?[/QUOTE]

Different types of batteries.

To use the knowledge that i have learned - and clarify things in this post; here it goes:

many and most car batteries run at 12v and (making this number up) 100 AH.
where as a cart battery (ie t-105 from trojan) runs at 6v and 185 AH.

this means that if you want a 96v system with 12v batteries, you need ( 96/12=8 ) 8 batteries. This now gives you (8*100=800) [B]800 AH @ 96v[/B] for your batt bank.

if you were to use cart batteries at 6v to get a 96v bank you need (96/6=16) 16 batteries. This gives you (16*185=2960) [B]2960 AH @ 96v.
[/B]
So at the same 96 volts with two types of batters you get 370% more power WITH THESE NUMBERS with 6v than you do with a 12v system.

I hope that makes sense - and i did the math right … someone PLEASE correct me if i’m wrong.

So at the same 96 volts with two types of batters you get 370% more power WITH THESE NUMBERS with 6v than you do with a 12v system.

I hope that makes sense - and i did the math right … someone PLEASE correct me if i’m wrong.

The idea is correct but if I’m not mistaken the math is wrong. You only add amp hours if you are running batteries is parallel. When you are running them in series you only add volts.

So for example if you have one 12v 100AH battery, two of them in parallel is still 12v but now 200AH. In series it is now 24v but still only 100AH for the total system.

If you have four 6v 100AH batteries, and two 12v 100AH batteries and placed both of them series you’d have the exact same volts and capacity.

What you’ll find is that you can get two 6v 200AH batteries for the same price as a 12v 100AH battery. In the EV world (which I’m a complete noobie to) this seems like a logical choice minus the extra weight.

Hopefully a third party can confirm

[QUOTE=bblocher;3474]The idea is correct but if I’m not mistaken the math is wrong. You only add amp hours if you are running batteries is parallel. When you are running them in series you only add volts.

So for example if you have one 12v 100AH battery, two of them in parallel is still 12v but now 200AH. In series it is now 24v but still only 100AH for the total system.

If you have four 6v 100AH batteries, and two 12v 100AH batteries and placed both of them series you’d have the exact same volts and capacity.

What you’ll find is that you can get two 6v 200AH batteries for the same price as a 12v 100AH battery. In the EV world (which I’m a complete noobie to) this seems like a logical choice minus the extra weight.

Hopefully a third party can confirm :)[/QUOTE]

dangit!! I knew my math was wrong…

doesnt that mean you HAVE to wire your batteries in a paralelle to get a higher voltage.

If you wire your batteries in a series your just going to have 12v, or 6v…

i’m confused…

Nope series is like this:
-xxxx+ -xxxx+ (like you’d put them in say a flashlight) Add volts here

Parallel is then:
-xxxx+
< >
-xxxx+

You’d connect all like polarity poles adding capacity but keep the same volts.

Brian

[QUOTE=bblocher;3484]Nope series is like this:
-xxxx+ -xxxx+ (like you’d put them in say a flashlight) Add volts here

Parallel is then:
-xxxx+
< >
-xxxx+

You’d connect all like polarity poles adding capacity but keep the same volts.

Brian[/QUOTE]

OK that makes sense. Then in an EV, how does one connect their batteries? To meet the voltage of your motor, you have to add your volts by connecting in a series?