need charger for system

System

Hi everyone,thanks for all the great knowledge on the board very help full. I seem to have a problem charging my system with a standard 10a marine charger, does charge some what but not to full power. Can anyone recommend a good charger that is moderately priced. My system right now has 2-120watt panel connected to 4- 6volt golf cart batteries, I don't know the specs on the batteries, and how long should it take to charge system if it is at 50% Thanks guys

niel

Re: need charger for system

i am assuming you are using the batteries in a 12v configuration giving roughly 440ah of capacity. 10amps is only about 2 and 1/4% of the capacity or greater than 20hrs to fully charge the batteries with no load or losses when 50% discharged. simply put you are undercharging them a bit so take a look at the iota chargers wind-sun offers. i'd recommend 20amps or greater to charge up your batteries with and the fact they are multistage charges means they're better for your batteries. you could use the 15amp charger if you're willing to wait longer than 15hrs to reach full charge from 50% dod. automotive chargers are unregulated so you could overcharge or undercharge batteries too easilly and take away the lifespan of your batteries. even watching them charge is difficult and once the top end voltage is reached you must disconnect it, but this will leave it only 80% charged because most automotive chargers don't accomodate the absorb stage.

System2

Re: need charger for system

thanks Niel, would a go power charger be equivalent to iota,looking at GP55a@12vdc

crewzer

Re: need charger for system

I’d agree with niel on the Iota DLS charger recommendation. Here are a few other things to consider:

1) Get a “12 V” charger with at least 20 A charge current (~5% of 440 Ah battery bank capacity). Anything up to ~55 A (~13% of capacity) would be OK for your flooded-cell battery bank.
2) You’ll need the optional IQ-4 Smart Charger adapter with the Iota controller. The DLS isn’t an automatic multi-stage charger without it.
3) Here’s a link to a good battery maintenance guide.
4) Figure on your net recharge to be ~80% of charger capacity. So, if you’re using a 20 A charger to recharge your 440 Ah battery bank from a 50% discharge, it’ll take (440 Ah x 50% / 20 A x 80%) = ~14 hours, give or take…
5) If your batteries are charged in a particularly cold or warm environment, you may need to consider a temperature compensated charger to avoid under- or over-charging the batteries. The Xantrex TrueCharge 40+ along with its optional remote battery temperature sensor is a good example of this type of charger.

BTW, what controller/charger are you using between the PV array and the batteries?

HTH,
Jim / crewzer

halfcrazy

Re: need charger for system

Also the iota dls chargers dont have a equilization setting. i beleive the xantrex does. not positive though.

crewzer

Re: need charger for system

1/2,

You're correct on both points.

Regards,
Jim / crewzer

Brock

Re: need charger for system

One thing to keep in mind is 95% of the chargers out there are not rated for continuous duty and are rated at their MAX output. So for a typical automotive charger might be rated at 10 amps might put out 10 amps at 12v (very low battery) but once the battery gets up to 13.0v the same charger might only put out 2-3 amps and if you try charging for long times like a larger battery bank the charger will likely overheat.

I can say the iota will put out its rated power the whole time and is rated for continuous duty. My DLS55 will put out 55 amps at 12v right up to 14.2v (with the smart charger). I am sure there are other good chargers out there, but I am simply amazed with iota, especially for the $. And they are about twice as efficient as a cheap car charger.

System2

Re: need charger for system

Thanks for the info, I called Go Power electric and asked for specs on there 55amp 12v charger,and was told to go to the iota website look up ther dls 55a charger, and went on to tell me iota makes the chargers for go power. only the name on the charger is different, and the price is cheaper. Has anyone else heard this?