sla question

[dogman dan]

Put three 12 ah and one 14 ah in series. That way, when the three 12 ah ones get low you'll be able to notice it with a voltmeter better. Keep track of the voltage of the 12 ah ones so you keep them from going below 80% discharged. It'll work fine, you just need to make sure you don't overdischarge the smaller ones by mistake. The main thing is watch the discharge level of the weakest battery once you know which one that is.

Of course, though, it's always best to have series connected cells matched as close as possible.

 

[Cold-E-Commuter]

Based upon responses I have decided to order a 4th 12v 14Ah battery. If I have to have a seperate 48v charger then I may as well have 2 packs. This allows me to have (1) 36V pack at (3) 12V 12Ah batteries with a specific charger for short rides and a 48V 14Ah pack with charger for longer rides. This also allows both packs to be on a float charge all the time where previously with (2) 36V packs and (1) charger this was not possible. This will also allow the ride home from work on the 48V 14Ah pack to happen followed by an immediate trip to the store with the 12V 12Ah pack without having to wait for a charger to finish. Thus allowing both packs to be used and keep the DOD to a minimum on both. Thanks all again for the great info.

 

[dequinox]

You don't have to have a 48v charger... you can charge the packs in parallel if you have a cutoff for the series connections. You'd end up with something like this:



Kick my posterior if I'm wrong here folks...

*EDIT:

This is obviously for a 36 volt setup... This will work, but I wouldn't really recommend it either. For this a 36v 2A charger would be faster, as a 48v 2A would be better for your setup above. Hooking a 2A parallel charge at 12v is going to take about .5A and feed it to each battery...taking about 4 times as long to charge.

 

[RTLSHIP]

I'm not sure about that. That diagrahm only has 3 batts. you need 4 --12v batts.
An easier way is to rewire for charging purposes and bring along 12v charger w/ the 36 v charger and charge 12v separately.
Still easier: an ebayer, digital2brother, is selling 48v SLA chargers 2.5amp at around $25. Fast charger.
I got one and all I had to do was modify the DC plug in. I simply soldered on a PC type power cord plug. It's also good on my lifepo packs. Charges them up about 98%.
I haven't tried my lifepo 48v 3amp charger on SLA as this might overcharge. Not sure?
Be careful.

 

[Cold-E-Commuter]

Thanks for the possible solution but I already have a 4th 12V 14Ah battery and a 48V Soneil charger on the way. This will allow me to keep both the 36V pack and the 48V pack on a constant float charge and not need to fuss with anything else. Happy riding.