Proper Sized Battery Charger

[joepiccaso]

I was trying to find a general question tread category as I believe this applies to any electric Golf Cart. And, someone can move it to its proper place if they like.

Anyway, I have a CC that I'm converting from 36V to 48V. I know I need a new charger for the 48V, but want to be sure I get the correct size. I will have a battery pack of 8-6V Trojan T-105 batteries. The Summit II 650W and the DeltaQ 650W chargers have been recommended. Both are onboard models. I read an article or a thread somewhere recently that for my battery pack I should get the 1050W versions in lieu of the 650W. It had something to do with the aH ratings and the 8 batteries and not the speed of the charging. I've already said more than I actually understand, but they commented that using the higher wattage charger would actually, make my batteries last longer and charge them better. This is what I'm trying to determine if I should get the bigger charger or stick with the recommended 650W. (13A vs 18-20A)

I have no desire to spend more money than I need to, but the difference in the two isn't a fortune and if it would help the life and condition of the batteries, then it may be worth it. I'm kinda at the point, if I don't get any definitive answers, I'll probably get the higher wattage charger. The batteries costs a lot more than the charger.

Thanks, Joe

[WalterM6]

The recommended charging rate is 1/10C. Where C is the Ah rating of the battery. So a 170Ah battery would be charged at 17A.

[joepiccaso]

Thanks, Walter. That sort of makes sense, but these batteries have several aH ratings. Which one do I use?

(From the Trojan spec sheet)
5-Hr Rate 185
10-Hr Rate 207
20-Hr Rate 225
100-Hr Rate 250

In that article I referenced the author was talking about the 20 Hr rating, but somehow related the charger needed to the total 8 batteries. So, if I understand what you are saying, and that is a big IF, so a single battery that has an aH rating of 170 would need a 17A charger? Sorry to sound so thick, but that doesn't make sense to me. It would seem that it should be some kind of total for the complete battery pack. And, I think the article was using the 20 Hr. aH number, which is 225 for these batteries. That would be 225 x 8 = 1800 aH. Maybe that's where the 1050W comes from. 1050W/48V = 21.9A. I'm lost. Thanks for the input. Joe

[Fairtax4me]

Most manufacturers go by the 20h rating.
For an 8-6v pack you will want the 1050w version of the Summit II.
They also make a 1425w version but that's far more than most golf cart packs will need, and only does 24 and 36v packs currently.