One Bad Apple…or Battery

You know the old saying about one bad apple causing the whole basket full of them to go bad. The same thing applies to batteries. I am there, now, and so is Mark. Like me, Mark seems intrigued by the Simpliphi lithium batteries, but is also interested in getting a little more life out of what he has. Here’s his note.

Ok, since my 8 Rolls L 16 batteries are 8+ years old, all but one (one cell is 20) are reading good PH, would it be better to get 1 battery new or replace with a Simpliphi? How much do they cost and how many would I need for a 24vDC, 3KW 220 volt a/c system used as a backup on house? It’s the old array and battery bank, we have since added a separate grid intertie array but like both.

We will first consider stretching the life of what you have. I am all for that, but I would NOT buy a new one to mix in with the 8 year olds. Have you given them a good, bubbling equalizing charge? Sometimes that will bring them back.

It may be that you can find a good used one at an industrial battery dealer. Stores like WalMart and Target use L16s in the floor scrubbers and trade them out. Maybe you could pick up a used one, and one that is a better match, for a hundred bucks or so.

Another option would be reconditioning. Here in Pensacola we have an outfit called Battery Guyz that will sell a reconditioned golf car battery for $60 with a one year warranty. Reconditioning includes desulfating, washing them out and refilling with fresh acid. Maybe an outfit like that could refresh your L16.

Now, as far as replacing one of your L16s with a Simpliphi…NO! The L16 is 6v. The Simpliphi is 24 or 48v, depending on the model. You can replace your entire collection of L16s with Simpliphi. Could you keep the one good bank of L16s and run parallel with Simpliphi? I don’t know the battery well enough to answer that question. I have the same question myself as I have two 48v EVs running in parallel to my house banks. It is a possibility I would look into by contacting the company. From what I read about the Battery Mangement System (BMS) I think it is a possibility, but you would probably have to separate the L16s offline when you equalized.

Let’s assume the worst, that we’ll have to swap out them all and start with his L16s’ specs. 8 of them on a 24v system is two strings. Depending on which version he bought, they are good for 390 or 445 amp hours. Let’s just round off to 400 since I hate math. 400ah x 24v x 2sets=19,200. Call it 20kw. Now, you can only safely draw down 10kw, so to replace the entire set of L16s with the Simpliphi 3.8kw units, you’ll need 10/3.8 or 3 of them. Because of all the rounding, they may give a little more drawdown than the 16 Rolls. One Simpliphi, I think, weighs less than an L16, and 3 of them will take up a whole lot less space.

Here’s the kicker. The Simpliphi is rated for 10,000 cycles. That’s more than any other lithium I have seen. 10,000 cycles is 27 years. If you are my age, then that is a “forever” battery. And no maintenance.

You’d have to get with Roberto or Tony for some hard prices, but I would guesstimate that 8 shiny new Rolls L16’s, a premium brand, would set you back around $3000, especially if you throw in postage on those heavy beasts. I think the retail on the Simpliphi is around $3000 each. So you end up paying maybe 3 times as much for 3 batteries as the pile of L16s. Yikes! BUT, now you have more capacity, less maintenance, and may never have to change a battery again. Oh, and bet that if an L16 is $350 today, it will be more 8 years from now!

It’s a bunch of money, I know, but if I am running the numbers right, that sure sounds like a bargain to me. Call Sun Electronics to get up-to-date numbers and an actual quote.

–Neal

Note that earlier I ran the numbers for 16 batteries instead of 8. That gave a completely whacked comparison, but the conclusion remains the same.