Helping a neighbor with a simple system: need battery replacement advice

[Old_Skewler]

I have a neighbor with a very basic system solar/battery system. He has (4) Trojan SPRE 06 415 (L16RE-B) Flooded Battery 6V connected in series for a 12V bank and a Midnite Solar Classic 200. His batteries have lasted for 14 years - - but are now very depleted - reading 12.3V charged.

His house is DC wired and he has minimal loads - a 3 USB ports to charge cell phones/iPad and a DC fridge. And a solar pump for well water.

For him to replace in kind it would cost him about $2,000 for (4) new Trojan batteries from RES: https://ressupply.com/batteries-and-enclosures/trojan-l16re-b-flooded-battery for a total capacity of 2.5 kWh x 4 = 10 kWh.

On one hand I feel like this could be the best approach for him: he got 14 years from this setup and sticking to the same formula would be safe.

On the other hand I wonder if there are any other flooded cell batteries he should be considering or even a lithium 12V pack.

Any insights from the group?

 

[Steve777]

So 4 6v batts in series is 24v nominally. Is that what you meant, or is it 2 in series, then parallel for 12v?

L-A batteries are actually more expensive than Li ones these days. If he is running a 24v system (or even a 12v) where are quite a few options for LFP batteries which could be used. One would have to confirm that the Classic 200 can be set for the appropriate voltages for an LFP battery (I think it can but have not checked).

Also, L-A batteries should only be drawn down to 50% or there abouts. So the 10KWH L-A batts actually give you 5KWH of usable power on a regular basis. LFP can go down to 20% (or some would say even lower), so you would only need maybe 6KWH of LFP batts to get the same usable power. Not a recommendation necessarily, but a popular Li batt would be the EG4-Lifepower4 24v battery; it runs ~$1150 for 5KWH of storage; and there are quite a few others to choose from.

There are some other considerations in the choice between L-A and LFP batts that you should visit and discuss. Temperature range of the battery location, max current draw, ability to fully charge the battery, and a few others things too.

But a LFP battery will likely come in significantly cheaper than replacement L-A ones. I am sure he won't miss watering the cells or moving all that lead around, and they would have some other advantages too (with some drawbacks such as low temp performance).

 

[sunshine_eggo]

If he's still good with applying best practices to FLA maintenance (or relying on pure luck if he didn't), and $2K is a pill he can swallow, it's probably for the best to stick with it.

If he's interested in expanding the usable capacity and decreasing maintenance, but learning and abiding by the needs of LFP, then THAT's probably best.

I'm battery agnostic. It's really about what the user wants more than what is "best."

 

[Old_Skewler]

So 4 6v batts in series is 24v nominally. Is that what you meant, or is it 2 in series, then parallel for 12v?

I see the confusion: his system is 12V, (2) series and (2) parallel.

L-A batteries are actually more expensive than Li ones these days.

After an initial research I realized this was the case. I was a bit surprised.

Not a recommendation necessarily, but a popular Li batt would be the EG4-Lifepower4 24v battery; it runs ~$1150 for 5KWH of storage; and there are quite a few others to choose from.

What other manufacturers should we consider for Li or L-A batteries? I have checked EG4 and Trojan prices. Should we consider Amazon vendors as well?

There are some other considerations in the choice between L-A and LFP batts that you should visit and discuss. Temperature range of the battery location, max current draw, ability to fully charge the battery, and a few others things too.

Yes, I went over the differences with him and because of the temperature charging limitation I think he is more inclined to stay with L-A.

 

[Old_Skewler]

If he's still good with applying best practices to FLA maintenance (or relying on pure luck if he didn't), and $2K is a pill he can swallow, it's probably for the best to stick with it.

Exactly my initial thoughts. I didnt ask about maintenance but I assume he did something right for those Trojan batteries to last 14 years... I was surprised.

If he's interested in expanding the usable capacity and decreasing maintenance, but learning and abiding by the needs of LFP, then THAT's probably best.

These are very old school minimalists with very small load. Ideally he wanted to find a replacement L-A battery just slightly larger that could fit in his isolated ground box, for a bit added capacity.

I am not sure how to find a slightly larger L-A battery than the current Trojan L16RE-B he's been using.

 

[NC_hydro]

He could go with a heated battery if low temp charging was a concern. I have a 12V LFP LiTime that has built-in heating. It lives in a non insulated wood box out in a field with two 135w panels keeping it topped up.

 

[Steve777]

Depending where he is in NYS, the batts may have to deal with significant cold for quite a while (think of the North country).

I don't know of any L-A batts which could fit in the same space as 4 L-16's which would give the right voltage with more capacity. Not saying they don't exist, I just am unaware of them. Getting more capacity in that space with Li would not be hard, but with the cold and other changes to his regime may not be attractive.

He might want to educate himself on Li batts, their care and maintenance, how his Modnite Classic will charge them, and cold temp use and then decide.

 

[seneysolar]

I have a neighbor with a very basic system solar/battery system. He has (4) Trojan SPRE 06 415 (L16RE-B) Flooded Battery 6V connected in series for a 12V bank and a Midnite Solar Classic 200. His batteries have lasted for 14 years - - but are now very depleted - reading 12.3V charged.

The SPRE is the solar premium line, they claim to have a coating that reduces sulfation on the plates. Yes they indeed last a long time.

His house is DC wired and he has minimal loads - a 3 USB ports to charge cell phones/iPad and a DC fridge. And a solar pump for well water.

Does he really need 4? Thats not much to power. Does he have an inverter with any ac loads? Maybe just 2 would be fine? How much solar is behind that classic 200?

For him to replace in kind it would cost him about $2,000 for (4) new Trojan batteries from RES: https://ressupply.com/batteries-and-enclosures/trojan-l16re-b-flooded-battery for a total capacity of 2.5 kWh x 4 = 10 kWh.

Find a local Trojan dealer. Buying online and paying shipping is cost prohibitive and if you need warranty it just won't be practical. These are 100lb batteries.

On one hand I feel like this could be the best approach for him: he got 14 years from this setup and sticking to the same formula would be safe.

Yes

 

[crossy]

Also, don't forget his old batteries have a not insignificant scrap value

 

[Mattb4]

Just replacing the old worn down batteries will give him more capacity. Chances are he has been running with reduced capacity for years now until it became too much. Batteries are consumables and need routine replacement.

 

[littleharbor2]

Look into forklift batteries. They come in many sizes.

 

[wpns]

Or golf cart batteries, which come in 6 and 12 volt sizes.

 

[sunshine_eggo]

Worth confirming the bank and array are right-sized. 14 years suggests pretty strongly that all is well, but it's always worth a look.

 

[Mattb4]

Worth confirming the bank and array are right-sized. 14 years suggests pretty strongly that all is well, but it's always worth a look.

You make a good point. The array after 14 years may also be producing less. Depending on all the needs just replacing the batteries may not work out.