trickle charging a 24v system

[hornadylnl]

Ok, I've got a military genset that will be here on Wed. I just ordered 2 12v optima batteries and tray adapters for it. You know the .gov can't use conventional anything on their equipment and the oem batteries for this genset are over $300 a piece. Now that I've just thrown down $400 on batteries for this genset, I want to make sure they're going to last and have a good charge when I need them.

I have a couple 12v battery tenders already. These 2 12v batteries will be wired in series to generate the 24v needed to start the generator. Can I just put a battery tenders 2 leads on the 2 terminals of one battery? If so, I'm thinking I'd have to unhook the batteries each time I hook the charger up. Does anyone know of a reasonably priced 24v trickle charger?

 

[shibumiseeker]

Buy two tenders, one for each battery and hook it to each. No big deal. Or use one and switch it between batteries occasionally. You don't need to unhook the batteries from each other or the genset either way.


But if you want a 24v charger and are willing to pay for it:

IOTA Engineering DLS-27-15 24VDC Battery Charger and Power Converter - 15 Amps for 24VDC

I use their 12v chargers for my RE system and they're top notch. Dunno how much, but if you shop around probably under a hundred shipped.

 

[hornadylnl]

Buy two tenders, one for each battery and hook it to each. No big deal. Or use one and switch it between batteries occasionally. You don't need to unhook the bateries from each other or the genset either way.


But if you want a 24v charger and are willing to pay for it:

IOTA Engineering DLS-27-15 24VDC Battery Charger and Power Converter - 15 Amps for 24VDC

I use their 12v chargers for my RE system and they're top notch. Dunno how much, but if you shop around probably under a hundred shipped.

Ok, I'll probably go the 2 tender route then. I wasn't sure if it would create a problem backfeeding the other battery or something. I know if you put a meter on just the 2 terminals of one battery, you still get just 12v and if you put the meter on the first and last terminal of each battery, you get 24v.

I've got 2 tenders already and really need a few more. One for the motorcycle, mower, etc.

 

[hornadylnl]

There was a guest brand on ebay that was a 24v 1.25 amp trickle charger that was reasonably priced but the optima website says to trickle at 1 amp or lower. It looks like the battery tender jr. is .75 amps. If I go that route, I can use them for other things as well then. I can get 2 of them shipped for about $54 on ebay.

 

[shibumiseeker]

There was a guest brand on ebay that was a 24v 1.25 amp trickle charger that was reasonably priced but the optima website says to trickle at 1 amp or lower. It looks like the battery tender jr. is .75 amps. If I go that route, I can use them for other things as well then. I can get 2 of them shipped for about $54 on ebay.

Depending on the electronics, the differences between the 1.25a and the .75a chargers are miniscule. The best chargers/tenders are selectable between flooded lead acid batteries and gel cells or cells like the Optima since each different type has slightly different float charging needs.

If you really want to make it simple, put the charger on a timer to float for a couple hours a day. That ensures peak readiness without the chance of battery damage.

 

[hornadylnl]

That sounds like a plan. I could have gotten 2 Napa batteries for about $240 but I liked the idea that I could get 2 mounting adapters to lock them down in the battery tray. Besides, what good is a genset when you can't get it started? Didn't want to spend this kind of money and then cheap out on the batteries.

A guy at church was telling me this morning that he built a generator. I guess he got a cheap Chinese long stroke diesel and put a big flywheel on it. He uses it to turn a large flywheel which in turn, turns a 15hp three phase motor. He said he'd give me the details on it. I might look into something like that if I can build it to run 6k or so. If not, I'll probably go with an MEP-002A for the geo thermal. I don't want to run the MEP-003A 24/7 at 1 gallon an hour.

 

[shibumiseeker]

Sounds like he got a Lister engine. They are not legal to import as is due to EPA restrictions, but have been imported as another use, then modified back. I'd love to have one, they are supposed to be able to essentially run forever. I'm getting 3000-4000 hours on the generators I use.

 

[kevman65]

Battery Tender makes a multiple bay charger, look into it. IIRC you can charge up to 6 batteries on it.

 

[jeremy]

It may already come with a Solar Battery Maintenace Systems installed...

 

[hornadylnl]

Sounds like he got a Lister engine. They are not legal to import as is due to EPA restrictions, but have been imported as another use, then modified back. I'd love to have one, they are supposed to be able to essentially run forever. I'm getting 3000-4000 hours on the generators I use.

He said he had the engine imported from china and put the rest of it together himself.

 

[hornadylnl]

It may already come with a Solar Battery Maintenace Systems installed...

I'll have to check I out.

I've got the Hubbell 100amp pin and sleeve plugs already. I don't know if I'm going to get regular no 2 service entrance cable for the wire or try to get actual cord. I'll be able to park the genset right next to my transfer switch.

Reading other forums, I've heard issues of running these generators without a load and causing wet stacking. Guys would make load banks of electric heaters to put a load on the generator. I thought about doing that and then it dawned on me. I've got 20 400 metal halide lights in my barn I can use.